NO. 4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC 269 



DR. BAUER ON SOLAR RADIATION AND TERRESTRIAL MAGNETISM 



In his paper of 191 5, Dr. Bauer finds a remarkable correlation 

 between the changes in solar radiation, as shown by values of the 

 solar constant possessing the requisite accuracy, and the changes in 

 the Earth's magnetism. This is the case not only with the more or 

 less sporadic changes from day to day, but also with the annual 

 changes of the solar constant and the annual magnetic changes. 

 " Since the solar constant changes occur only approximately in ac- 

 cordance with sun spot activity, and since the magnetic changes are 

 found to conform closely to those in the solar constant, an explana- 

 tion is found as to why the irregularities in the magnetic secular 

 change do not always synchronize with changes in solar activity as 

 measured by the sun spot numbers, nor correspond in magnitude to 

 them." " The relation between changes in solar constant and mag- 

 netic constant is of such a definite character as to make it appear 

 that one set of changes may furnish an effective control over the 

 other." " Just how far changes in solar constant," as measured by 

 the pyrheliometer, " may be taken as a true measure of those changes 

 in the sun's activity, which really are the cause, directly and indi- 

 rectly, of the magnetic changes, requires further investigation." 

 Dr. Bauer also finds that the magnetic efifects observed during 

 total solar eclipses are in general harmony with the magnetic changes 

 correlated with changes in the solar constant, as measured by the 

 pyrheliometer. 



DR. ABBOT ON FLUCTUATIONS IN SOLAR RADIATION, SUN SPOTS, 

 AND TERRESTRIAL TEMPERATURE 



In his paper on " The Sun and the Weather " Dr. Abbot [1917] 

 gives a comparison between the mean annual values of the solar 

 constant as obtained by the observations at Mount Wilson for the 

 years from 1905 to 1915 (except 1907) and the relative numbers 

 of the sun spots. He found that the maximum mean annual value 

 of the solar constant observed occurred in 1905 when there also 

 was a maximum of sun spots, and the minimum annual value of the 

 solar constant occurred in 1913 when there was an exceptional mini- 

 mum of sun spots. But otherwise the fluctuations in the value of 

 the solar constant do not always correspond with the fluctuations in 

 the sun spot numbers. There is an especially marked disagreement 

 in this respect in the values obtained for 191 2 when the solar con- 

 stant had a comparatively high value while the sun spot number 

 was near its minimum. But on the whole it may be said that a low 



